Just before the holidays Al wrapped up his review of Crucial's 1TB MX500 SATA drive, which is worth revisiting. The most attractive feature of this SSD is its price, currently for $260 you can grab 1TB of fast storage; not quite in line with Ryan's law but getting close. The performance of the TLC SSD does not suffer because of the low price, while it can't match a current generation M.2 NVMe drive it competes with more expensive SATA based SSDs. If you are concerned about endurance, remember that TLC has matured and Crucial rates this drive as 360TB written over five year. Drop by the Guru of 3D to contrast their benchmarks with our own.

"Crucial announced their new MX500 series SSD, we put the 1TB model to the test. At 25 cents per GB, these units are all about value for money. But they do not compromise on performance, no Sir. The MX500 remains very fast and very effective for the money you put down on that counter."

Introduction, Specifications and Packaging

Introduction:

Crucial and their parent company Micron have certainly launched their share of SSDs over the years. Product launches have effectively toggled back and forth between both names, with Crucial handling the upgrade market while Micron proper handles the OEM side of things. Both sides have one thing in common - solid performing SSDs at a budget-friendly price point. Having the best performing SSD on the market is great, but does nobody any good if the majority of purchasers can't afford it.

We had Micron out to discuss the MX500 before we completed our testing. Here is the full discussion video:

Specifications:

Micron® 3D TLC NAND Flash

RoHS-compliant package

SATA 6 Gb/s interface

TCG/Opal 2.0-compliant self-encrypting drive (SED)

Compatible with Microsoft eDrive®

Hardware-based AES-256 encryption engine

Performance (ALL CAPACITIES):

Sequential 128KB READ: Up to 560 MB/s

Sequential 128KB WRITE: Up to 510 MB/s

Random 4KB READ: Up to 95,000 IOPS

Random 4KB WRITE: Up to 90,000 IOPS

Power consumption:

250GB: <3.5W

500GB: <4.5W

1000GB/2000GB: <5.0W

Endurance – total bytes written (TBW):

250GB: 100TB

500GB: 180TB

1TB: 360TB

2TB: 700TB

A few points from these impressive specs:

Performance specs are common across *all* capacities. Yes, even the smallest model is rated to perform as well as the largest.

Endurance is very high, especially for TLC NAND. Samsung's 850 EVO 500GB and 1TB models are rated at 150TB. Heck, the 850 PRO 1TB is only rated at 300TBW. Sure that's the same rating carried up from the 512GB model of the same, but it's not Micron's fault that Samsung opted to capacity-bracket their endurance ratings.

The change process technology continues to have a negative effect on DRAM supplies and according to the story posted on Electronics Weekly there is no good news in sight. The three major vendors, Samsung, SK Hynix and Micron are all slowing production as a result of new fabs being built and existing production lines upgraded for new process technology such as EUV. This will ensure that prices continue to slowly creep up over the remainder of this year and likely into 2018. Drop by for more information on the challenges each are facing.

"While overall DRAM demand will remain high in 2018, new fabs being planned will not be ready for mass production until 2019 at the earliest."

DigiTimes is the bearer of bad news for fans of GPUs, as the supply challenges which have marked 2017 are now spreading to GDDR5(x). This month the price has spiked up just over 30% and that trend is going to continue into September and perhaps beyond. This will not have an immediate effect on the MSRPs of graphics cards, not that we would notice due to the price inflation from the current mining craze however it will reduce the margins that NVIDIA and AMD receive from sales. They do not specifically mention AMD in the article, nor HBM2, however the same companies fabricate both so there are likely to be repercussions felt by both technologies. On the positive side, flash storage prices are reported to have stabilized; so we have that going for us.

"August quotes for RAMs used in VGA graphics cards have risen to US$8.50, up by 30.8% from US$6.50 in July. Both RAM industry leaders Samsung Electronics and SK Hynix have allocated part of their VGA RAM production capacities to producing memories for servers and handsets, fueling the price rally."

We were extremely impressed with the Micron 9100 Enterprise SSDs. They are still the fastest NAND flash SSDs we've tested to date, but they were built on planar NAND, and we know everyone is replacing their flat flash with more cost efficient 3D NAND. Same goes for the 9200:

Highlights for the new models are IMFT 3D NAND running in TLC mode and a new controller capable of PCIe 3.0 x8 (HHHL form factor only - U.2 is only a x4 interface). Here are the detailed specs:

Improvements for the x4 models are marginal upgrades over the 9100, but the x8 variants bump up the maximum performance to 900,000 IOPS and 5.5GB/s! These should be shipping by the end of the month, and we will review them as they come in.

This would imply that any impact on Micron's RAM production, even if nowhere near the amount mentioned by the press, would have a large effect on the market in the coming quarters. Samsung will certainly try to capture some of this demand, but the upgrades to their Fabs are still a while off and they are already operating at close to maximum capacity. Fingers crossed we don't hear bad news from GLOFO tomorrow morning!

"Micron Technology has issued a statement regarding recent reports about its fabrication facility in Taoyuan, Taiwan. Micron clarified that there was no nitrogen leaking incident nor evacuation of personnel. A minor event did occurred at the facility, but operations are recovering speedily without material impact to the business."

JEDEC made the GDDR5X memory standard official almost a year and a half ago where it launched at 10 Gbps and quickly hit 12 Gbps. Set to bridge the gap between GDDR5 and the upcoming GDDR6, the “G5X” standard is quickly catching up to and matching the speeds that GDDR6 will run at.

Specifically, Micron’s Graphics Design Team in Munich was able to achieve an impressive 16 Gbps in their high speed test environment. The team was able to hit 16 Gbps on a “meaningful sampling” of its mass production GDDR5X silicon which makes the feat much more impressive as it means these higher speeds are moving closer to reality than theory. Micron measured a PRBS11 (psuedorandom binary sequence) pattern read at 16 Gbps using an oscilloscope and also showed off a chart that compared the stable data rate timing margin versus data rate from 10 Gbps to 16 Gbps.

In addition to teasing the 16 Gbps memory speed (it will be awhile yet before we see products like graphics cards running memory at those speeds), Micron announced that it expects to being mass productions of GDDR6 chips in early 2018. GDDR6 will see a new (larger) FBGA1180 package, faster base sort speeds (GDDR6 will start at 12Gbps vs G5X's 10Gbps), and moving to a dual channel approach with channels that will have half as many I/O links (GDDR5X is x16/x32 while GDDR6 will be x8/16 per channel). It will be interesting to see how this move will stack up to G5X, but in theory Micron will be able to push clocks even higher (maybe even higher than 16 Gbps) by having more but simpler channels (and it may be easier for graphics card manufacturers to wire up their cards to the memory chips.

SK Hynix, who showed off its first GDDR6 chip at GTC, appears to be following the same I/O design as Micron with two channel memory at x8 or x16 per channel.

Are you ready for faster GDDR5X? Hopefully these new faster G5X chips come out soon to give AMD and NVIDIA a more appealing alternative to HBM and HBM2 for mid-range and high end consumer graphics cards since High Bandwidth Memory seems to still be suffering from limited supply and is holding the GPU guys back on being able to crank up the production lines!

Introduction, How PCM Works, Reading, Writing, and Tweaks

I’ve seen a bit of flawed logic floating around related to discussions about 3D XPoint technology. Some are directly comparing the cost per die to NAND flash (you can’t - 3D XPoint likely has fewer fab steps than NAND - especially when compared with 3D NAND). Others are repeating a bunch of terminology and element names without taking the time to actually explain how it works, and far too many folks out there can't even pronounce it correctly (it's spoken 'cross-point'). My plan is to address as much of the confusion as I can with this article, and I hope you walk away understanding how XPoint and its underlying technologies (most likely) work. While we do not have absolute confirmation of the precise material compositions, there is a significant amount of evidence pointing to one particular set of technologies. With Optane Memory now out in the wild and purchasable by folks wielding electron microscopes and mass spectrometers, I have seen enough additional information come across to assume XPoint is, in fact, PCM based.

XPoint memory. Note the shape of the cell/selector structure. This will be significant later.

While we were initially told at the XPoint announcement event Q&A that the technology was not phase change based, there is overwhelming evidence to the contrary, and it is likely that Intel did not want to let the cat out of the bag too early. The funny thing about that is that both Intel and Micron were briefing on PCM-based memory developments five years earlier, and nearly everything about those briefings lines up perfectly with what appears to have ended up in the XPoint that we have today.

Some die-level performance characteristics of various memory types. source

The above figures were sourced from a 2011 paper and may be a bit dated, but they do a good job putting some actual numbers with the die-level performance of the various solid state memory technologies. We can also see where the ~1000x speed and ~1000x endurance comparisons with XPoint to NAND Flash came from. Now, of course, those performance characteristics do not directly translate to the performance of a complete SSD package containing those dies. Controller overhead and management must take their respective cuts, as is shown with the performance of the first generation XPoint SSD we saw come out of Intel:

There have been a few very vocal folks out there chanting 'not good enough', without the basic understanding that the first publicly available iteration of a new technology never represents its ultimate performance capabilities. It took NAND flash decades to make it into usable SSDs, and another decade before climbing to the performance levels we enjoy today. Time will tell if this holds true for XPoint, but given Micron's demos and our own observed performance of Intel's P4800X and Optane Memory SSDs, I'd argue that it is most certainly off to a good start!